/*
 Copyright  2002-2007 MySQL AB, 2008 Sun Microsystems
 All rights reserved. Use is subject to license terms.

  The MySQL Connector/J is licensed under the terms of the GPL,
  like most MySQL Connectors. There are special exceptions to the
  terms and conditions of the GPL as it is applied to this software,
  see the FLOSS License Exception available on mysql.com.

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; version 2 of the
  License.

  This program is distributed in the hope that it will be useful,  
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  02110-1301 USA

 */

package com.mysql.jdbc.profiler;

import java.util.Date;

import com.mysql.jdbc.Util;

/**
 * @author mmatthew
 */
public class ProfilerEvent {

	/**
	 * A Profiler warning event
	 */
	public static final byte TYPE_WARN = 0;

	/**
	 * Profiler creating object type event
	 */
	public static final byte TYPE_OBJECT_CREATION = 1;

	/**
	 * Profiler event for prepared statements being prepared
	 */
	public static final byte TYPE_PREPARE = 2;

	/**
	 * Profiler event for a query being executed
	 */
	public static final byte TYPE_QUERY = 3;

	/**
	 * Profiler event for prepared statements being executed
	 */
	public static final byte TYPE_EXECUTE = 4;

	/**
	 * Profiler event for result sets being retrieved
	 */
	public static final byte TYPE_FETCH = 5;

	/**
	 * Profiler event for slow query
	 */
	public static final byte TYPE_SLOW_QUERY = 6;
	
	/**
	 * Type of event
	 */
	protected byte eventType;

	/**
	 * Associated connection (-1 for none)
	 */
	protected long connectionId;

	/**
	 * Associated statement (-1 for none)
	 */
	protected int statementId;

	/**
	 * Associated result set (-1 for none)
	 */
	protected int resultSetId;

	/**
	 * When was the event created?
	 */
	protected long eventCreationTime;

	/**
	 * How long did the event last?
	 */
	protected long eventDuration;

	/**
	 * What units was the duration measured in?
	 */
	protected String durationUnits;
	
	/**
	 * The hostname the event occurred on (as an index into a dictionary, used
	 * by 'remote' profilers for efficiency)?
	 */
	protected int hostNameIndex;

	/**
	 * The hostname the event occurred on
	 */
	protected String hostName;

	/**
	 * The catalog the event occurred on (as an index into a dictionary, used by
	 * 'remote' profilers for efficiency)?
	 */
	protected int catalogIndex;

	/**
	 * The catalog the event occurred on
	 */
	protected String catalog;

	/**
	 * Where was the event created (as an index into a dictionary, used by
	 * 'remote' profilers for efficiency)?
	 */
	protected int eventCreationPointIndex;

	/**
	 * Where was the event created (as a Throwable)?
	 */
	protected Throwable eventCreationPoint;

	/**
	 * Where was the event created (as a string description of the
	 * eventCreationPoint)?
	 */
	protected String eventCreationPointDesc;

	/**
	 * Optional event message
	 */
	protected String message;

	/**
	 * Creates a new profiler event
	 * 
	 * @param eventType
	 *            the event type (from the constants TYPE_????)
	 * @param hostName
	 *            the hostname where the event occurs
	 * @param catalog
	 *            the catalog in use
	 * @param connectionId
	 *            the connection id (-1 if N/A)
	 * @param statementId
	 *            the statement id (-1 if N/A)
	 * @param resultSetId
	 *            the result set id (-1 if N/A)
	 * @param eventCreationTime
	 *            when was the event created?
	 * @param eventDurationMillis
	 *            how long did the event last?
	 * @param eventCreationPointDesc
	 *            event creation point as a string
	 * @param eventCreationPoint
	 *            event creation point as a Throwable
	 * @param message
	 *            optional message
	 */
	public ProfilerEvent(byte eventType, String hostName, String catalog,
			long connectionId, int statementId, int resultSetId,
			long eventCreationTime, long eventDuration, String durationUnits,
			String eventCreationPointDesc, Throwable eventCreationPoint,
			String message) {
		this.eventType = eventType;
		this.connectionId = connectionId;
		this.statementId = statementId;
		this.resultSetId = resultSetId;
		this.eventCreationTime = eventCreationTime;
		this.eventDuration = eventDuration;
		this.durationUnits = durationUnits;
		this.eventCreationPoint = eventCreationPoint;
		this.eventCreationPointDesc = eventCreationPointDesc;
		this.message = message;
	}

	/**
	 * Returns the description of when this event was created.
	 * 
	 * @return a description of when this event was created.
	 */
	public String getEventCreationPointAsString() {
		if (this.eventCreationPointDesc == null) {
			this.eventCreationPointDesc = Util
					.stackTraceToString(this.eventCreationPoint);
		}

		return this.eventCreationPointDesc;
	}

	/**
	 * Returns a representation of this event as a String.
	 * 
	 * @return a String representation of this event.
	 */
	public String toString() {
		StringBuffer buf = new StringBuffer(32);

		switch (this.eventType) {
		case TYPE_EXECUTE:
			buf.append("EXECUTE");
			break;

		case TYPE_FETCH:
			buf.append("FETCH");
			break;

		case TYPE_OBJECT_CREATION:
			buf.append("CONSTRUCT");
			break;

		case TYPE_PREPARE:
			buf.append("PREPARE");
			break;

		case TYPE_QUERY:
			buf.append("QUERY");
			break;

		case TYPE_WARN:
			buf.append("WARN");
			break;
		case TYPE_SLOW_QUERY:
			buf.append("SLOW QUERY");
			break;
		default:
			buf.append("UNKNOWN");
		}

		buf.append(" created: ");
		buf.append(new Date(this.eventCreationTime));
		buf.append(" duration: ");
		buf.append(this.eventDuration);
		buf.append(" connection: ");
		buf.append(this.connectionId);
		buf.append(" statement: ");
		buf.append(this.statementId);
		buf.append(" resultset: ");
		buf.append(this.resultSetId);

		if (this.message != null) {
			buf.append(" message: ");
			buf.append(this.message);

		}

		if (this.eventCreationPointDesc != null) {
			buf.append("\n\nEvent Created at:\n");
			buf.append(this.eventCreationPointDesc);
		}

		return buf.toString();
	}

	/**
	 * Unpacks a binary representation of this event.
	 * 
	 * @param buf
	 *            the binary representation of this event
	 * @return the unpacked Event
	 * @throws Exception
	 *             if an error occurs while unpacking the event
	 */
	public static ProfilerEvent unpack(byte[] buf) throws Exception {
		int pos = 0;

		byte eventType = buf[pos++];
		long connectionId = readInt(buf, pos);
		pos += 8;
		int statementId = readInt(buf, pos);
		pos += 4;
		int resultSetId = readInt(buf, pos);
		pos += 4;
		long eventCreationTime = readLong(buf, pos);
		pos += 8;
		long eventDuration = readLong(buf, pos);
		pos += 4;
		
		byte[] eventDurationUnits = readBytes(buf, pos);
		pos += 4;
		
		if (eventDurationUnits != null) {
			pos += eventDurationUnits.length;
		}
		
		int eventCreationPointIndex = readInt(buf, pos);
		pos += 4;
		byte[] eventCreationAsBytes = readBytes(buf, pos);
		pos += 4;

		if (eventCreationAsBytes != null) {
			pos += eventCreationAsBytes.length;
		}

		byte[] message = readBytes(buf, pos);
		pos += 4;

		if (message != null) {
			pos += message.length;
		}

		return new ProfilerEvent(eventType, "", "", connectionId, statementId,
				resultSetId, eventCreationTime, eventDuration,
				new String(eventDurationUnits, "ISO8859_1"),
				new String(eventCreationAsBytes, "ISO8859_1"), null,
				new String(message, "ISO8859_1"));
	}

	/**
	 * Creates a binary representation of this event.
	 * 
	 * @return a binary representation of this event
	 * @throws Exception
	 *             if an error occurs while packing this event.
	 */
	public byte[] pack() throws Exception {

		int len = 1 + 4 + 4 + 4 + 8 + 4 + 4;

		byte[] eventCreationAsBytes = null;

		getEventCreationPointAsString();

		if (this.eventCreationPointDesc != null) {
			eventCreationAsBytes = this.eventCreationPointDesc
					.getBytes("ISO8859_1");
			len += (4 + eventCreationAsBytes.length);
		} else {
			len += 4;
		}

		byte[] messageAsBytes = null;

		if (messageAsBytes != null) {
			messageAsBytes = this.message.getBytes("ISO8859_1");
			len += (4 + messageAsBytes.length);
		} else {
			len += 4;
		}
		
		byte[] durationUnitsAsBytes = null;
		
		if (durationUnits != null) {
			durationUnitsAsBytes = this.durationUnits.getBytes("ISO8859_1");
			len += (4 + durationUnitsAsBytes.length);
		} else {
			len += 4;
		}

		byte[] buf = new byte[len];

		int pos = 0;

		buf[pos++] = this.eventType;
		pos = writeLong(this.connectionId, buf, pos);
		pos = writeInt(this.statementId, buf, pos);
		pos = writeInt(this.resultSetId, buf, pos);
		pos = writeLong(this.eventCreationTime, buf, pos);
		pos = writeLong(this.eventDuration, buf, pos);
		pos = writeBytes(durationUnitsAsBytes, buf, pos);
		pos = writeInt(this.eventCreationPointIndex, buf, pos);

		if (eventCreationAsBytes != null) {
			pos = writeBytes(eventCreationAsBytes, buf, pos);
		} else {
			pos = writeInt(0, buf, pos);
		}

		if (messageAsBytes != null) {
			pos = writeBytes(messageAsBytes, buf, pos);
		} else {
			pos = writeInt(0, buf, pos);
		}

		return buf;
	}

	private static int writeInt(int i, byte[] buf, int pos) {

		buf[pos++] = (byte) (i & 0xff);
		buf[pos++] = (byte) (i >>> 8);
		buf[pos++] = (byte) (i >>> 16);
		buf[pos++] = (byte) (i >>> 24);

		return pos;
	}

	private static int writeLong(long l, byte[] buf, int pos) {
		buf[pos++] = (byte) (l & 0xff);
		buf[pos++] = (byte) (l >>> 8);
		buf[pos++] = (byte) (l >>> 16);
		buf[pos++] = (byte) (l >>> 24);
		buf[pos++] = (byte) (l >>> 32);
		buf[pos++] = (byte) (l >>> 40);
		buf[pos++] = (byte) (l >>> 48);
		buf[pos++] = (byte) (l >>> 56);

		return pos;
	}

	private static int writeBytes(byte[] msg, byte[] buf, int pos) {
		pos = writeInt(msg.length, buf, pos);

		System.arraycopy(msg, 0, buf, pos, msg.length);

		return pos + msg.length;
	}

	private static int readInt(byte[] buf, int pos) {
		return (buf[pos++] & 0xff) | ((buf[pos++] & 0xff) << 8)
				| ((buf[pos++] & 0xff) << 16) | ((buf[pos++] & 0xff) << 24);

	}

	private static long readLong(byte[] buf, int pos) {
		return (long) (buf[pos++] & 0xff) | ((long) (buf[pos++] & 0xff) << 8)
				| ((long) (buf[pos++] & 0xff) << 16)
				| ((long) (buf[pos++] & 0xff) << 24)
				| ((long) (buf[pos++] & 0xff) << 32)
				| ((long) (buf[pos++] & 0xff) << 40)
				| ((long) (buf[pos++] & 0xff) << 48)
				| ((long) (buf[pos++] & 0xff) << 56);
	}

	private static byte[] readBytes(byte[] buf, int pos) {
		int length = readInt(buf, pos);

		pos += 4;

		byte[] msg = new byte[length];
		System.arraycopy(buf, pos, msg, 0, length);

		return msg;
	}

	/**
	 * Returns the catalog in use
	 * 
	 * @return the catalog in use
	 */
	public String getCatalog() {
		return this.catalog;
	}

	/**
	 * Returns the id of the connection in use when this event was created.
	 * 
	 * @return the connection in use
	 */
	public long getConnectionId() {
		return this.connectionId;
	}

	/**
	 * Returns the point (as a Throwable stacktrace) where this event was
	 * created.
	 * 
	 * @return the point where this event was created
	 */
	public Throwable getEventCreationPoint() {
		return this.eventCreationPoint;
	}

	/**
	 * Returns the time (in System.currentTimeMillis() form) when this event was
	 * created
	 * 
	 * @return the time this event was created
	 */
	public long getEventCreationTime() {
		return this.eventCreationTime;
	}

	/**
	 * Returns the duration of the event in milliseconds
	 * 
	 * @return the duration of the event in milliseconds
	 */
	public long getEventDuration() {
		return this.eventDuration;
	}

	/**
	 * Returns the units for getEventDuration()
	 */
	public String getDurationUnits() {
		return this.durationUnits;
	}
	
	/**
	 * Returns the event type flag
	 * 
	 * @return the event type flag
	 */
	public byte getEventType() {
		return this.eventType;
	}

	/**
	 * Returns the id of the result set in use when this event was created.
	 * 
	 * @return the result set in use
	 */
	public int getResultSetId() {
		return this.resultSetId;
	}

	/**
	 * Returns the id of the statement in use when this event was created.
	 * 
	 * @return the statement in use
	 */
	public int getStatementId() {
		return this.statementId;
	}

	/**
	 * Returns the optional message for this event
	 * 
	 * @return the message stored in this event
	 */
	public String getMessage() {
		return this.message;
	}
}